1643166 has 84 divisors (see below), whose sum is σ = 4485672. Its totient is φ = 449064.

The previous prime is 1643141. The next prime is 1643171. The reversal of 1643166 is 6613461.

1643166 is a `hidden beast` number, since 1 + 643 + 16 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 71431 + ... + 71453.

2^1643166 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2242836).

1643166 is an abundant number, since it is smaller than the sum of its proper divisors (2842506).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1643166 is an equidigital number, since it uses as much as digits as its factorization.

1643166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 35 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 1643166 is about 1281.8603668107. The cubic root of 1643166 is about 118.0032078032.

The spelling of 1643166 in words is "one million, six hundred forty-three thousand, one hundred sixty-six".